Help! Choosing the right controller... Confused

[Sharding1995]

Hi, Im building a budget ebike(first time). wanted something not too complicated so ive gone with 1000w direct drive brushless, sensored rear wheel hub motor. it comes with sw900 display and a controller that is apparently good upto 26a at 48v. problem is i have no way to set different power settings for the pas system. im pretty sure its max power through pas 1 to 5. in the future ill probably upgrade to mid drive bafang motor (once i know what im doing) lol. Right now i want to be able to have some control in pas. I've read that kt screen and controller will give me the control, setting amps etc... i also know that cycle analyst will do the same but its hard to get hold of in uk and very expensive. i need to upgrade the controller anyway.

My questions are;
1.can i use a kt controller with the sw900?
2. will the kt controller with/without kt lcd give me what im after?
3. are there any alternatives to kt? is kt a brand? or do different brand manufacture kt controllers?

Appreciate any response and help, ive been looking everywhere for this sort of information ..

 

[Nealh]

KT are made by Keunteng electronics ,China. They are one of the best after market readily available controllers which are easy to set up with current values ranging from 12a - 40a depending on the model bought. For reliable higher current models you need the 9 or 12 fet models, controller and lcd up to about £100 and advisable to get a PAS sensor as well.
Look on Aliexpress or Topbikekit where all various KT stuff is available.

You can't get differing PAS level input without an LCD to send the info to and from the controller.
KT controller are only 100% with KT led/lcd others might work but you only might get 80 - 90% compatibility with some functions not working correctly.

Other cheaper controller kits out there usually only allow 12 - 15 a.

 

[Nealh]

im pretty sure its max power through pas 1 to 5. in the future ill probably upgrade to mid drive bafang motor (once i know what im doing) lol. Right now i want to be able to have some control in pas. I've read that kt screen and controller will give me the control, setting amps etc... i also know that cycle analyst will do the same but its hard to get hold of in uk and very expensive. i need to upgrade the controller anyway.

From your description max power in all PAS levels is speed control, each PAS gives max current but a differing max speed in each PAS level.
The KT gives you the option of speed control, the default setting is current control.
In each PAS level you get a differing current input with max speed in each PAS level.
Typically only 100% current in PAS 5 or throttle, PAS 1 13%, PAS 2 20%, PAS 3 33% & PAS 4 50%.

 

[sjpt]

Looks as if you already have the LCD you need (sw900 display ). Quick search looks as if you should be able to enable the different power modes.

How to Set LCD Display Parameters

Turn on the kit by pressing and holding the M button for 4-5 seconds. Press and hold the Up and Down arrows for 4-5 seconds to enter the settings panel of your SW900 / S830 LCD Displays. The following are the programs/parameters and what they stand for: P01 Background luminance. 1 is the...

ebikeling.com

Maybe I misread your first post and you have already tried that? Not sure why you say i need to upgrade the controller anyway.

 

[Sharding1995]

KT are made by Keunteng electronics ,China. They are one of the best after market readily available controllers which are easy to set up with current values ranging from 12a - 40a depending on the model bought. For reliable higher current models you need the 9 or 12 fet models, controller and lcd up to about £100 and advisable to get a PAS sensor as well.
Look on Aliexpress or Topbikekit where all various KT stuff is available.

You can't get differing PAS level input without an LCD to send the info to and from the controller.
KT controller are only 100% with KT led/lcd others might work but you only might get 80 - 90% compatibility with some functions not working correctly.

Other cheaper controller kits out there usually only allow 12 - 15 a.

Thanks for the info, probably order one in next few weeks

 

[Sharding1995]

From your description max power in all PAS levels is speed control, each PAS gives max current but a differing max speed in each PAS level.
The KT gives you the option of speed control, the default setting is current control.
In each PAS level you get a differing current input with max speed in each PAS level.
Typically only 100% current in PAS 5 or throttle, PAS 1 13%, PAS 2 20%, PAS 3 33% & PAS 4 50%.

It seems to be the same problem across the board when people have bought voilemart conversion kits... they're cheap, motors seem good but everyone just gets full throttle power as soon as they peddle, settings dont seem to effect it.. few videos on YouTube..
So If i bought a kt controller and lcd display and set up pas settings that you have suggested, would that allow me to actually put some work into peddling and work up a sweat? I want an ebike yet I dont want to be too lazy...

 

[Sharding1995]

Looks as if you already have the LCD you need (sw900 display ). Quick search looks as if you should be able to enable the different power modes.

How to Set LCD Display Parameters

Turn on the kit by pressing and holding the M button for 4-5 seconds. Press and hold the Up and Down arrows for 4-5 seconds to enter the settings panel of your SW900 / S830 LCD Displays. The following are the programs/parameters and what they stand for: P01 Background luminance. 1 is the...

ebikeling.com

Maybe I misread your first post and you have already tried that? Not sure why you say i need to upgrade the controller anyway.

Everyone who has bought the voilemart 1000w kit has same problem, pas is that dangerous its unusable.. I've been through all the settings but doesn't matter if I'm in PAS 1 or pas 5, it gives the same speed and same ecceleration, 100%

 

[Nealh]

Thought cheap kits use cheap crappy controller systems with little control, I doubt a KT will be much better a lot of people will use a CA to deliver the power.
Tbh the D/D hubs need a good battery and current to get the best out of them, running at low current isn't of much use.
The KT with lcd you can vary the controller current if you wish & yes with the 5 PAS levels you can feel the differing effort needed in each PAS esp on inclines when a load/current is applied. The issue with D/D hubs is they are very poor/inefficient on inclines unless a good battery is paired to the controller to deliver the current.

Most people would be better off with a 250w geared hub over a D/D hub, best use for a D/D hub is for flat terrain at a faster road speed.

 

[Nealh]

So If i bought a kt controller and lcd display and set up pas settings that you have suggested, would that allow me to actually put some work into peddling and work up a sweat? I want an ebike yet I dont want to be too lazy...

The PAS level %'s I mentioned are preset, you can't change them you get the approx % in each PAS level based on the max current the controller is set for. For more control then you will need the CA.
If you get the KT you can dial down the current using C5 setting so if you get a 30a/40a version you can dial down the max current, as with all these types of hubs the power required is governed by the battery and it needs to be a very good celled one that is able to continuously deliver the required current.
A D/D run at the lower PAS %'s will be gutless and inefficient, they demand power and are inefficient at low speed/power. More of the battery energy will be wasted as heat instead of delivering the power.

Buyers get lulled in to the cheap kits and the hype of the speed rating, to go the D/D route you need ideally to spend a lot more money then what a good geared hub kit costs. The battery is the all important factor for D/D hubs, even 48v isn't exactly great for D/D you need more current and voltage typically 60v for a more effiecient moped.

 

[sjpt]

As Nealh says, a lot of people fall into the large DD trap, because of (apparent) price and (apparent) superpower. I certainly might have done so if I had not read extensively (mainly on this site) before buying. Probably usually first time ebikers wanting to test the waters and see whether ebike is for them, and so want to minimize budget. A quick look on ebay makes £300 appear a feasible budget, and £500/£600 seems an awful lot more for what may just end up as a few weeks (days?) experiment.

(1) Anyone who reads this site in advance is unlikely to fall into that trap, and if they ask a 'what should I buy' question are likely to very strongly warned of it.

(2) However, I wonder if there are clear suggestions for the best thing to do for people who have fallen in, and come to this site for suggestions of the next best steps they should take?

I and many others can help with (1). On the other hand, I (and I think many of us) don't have the knowledge to make a constructive contribution to (2). Perhaps it would be worth a sticky thread contributed to by those that do?

 

[Sharding1995]

The PAS level %'s I mentioned are preset, you can't change them you get the approx % in each PAS level based on the max current the controller is set for. For more control then you will need the CA.
If you get the KT you can dial down the current using C5 setting so if you get a 30a/40a version you can dial down the max current, as with all these types of hubs the power required is governed by the battery and it needs to be a very good celled one that is able to continuously deliver the required current.
A D/D run at the lower PAS %'s will be gutless and inefficient, they demand power and are inefficient at low speed/power. More of the battery energy will be wasted as heat instead of delivering the power.

Buyers get lulled in to the cheap kits and the hype of the speed rating, to go the D/D route you need ideally to spend a lot more money then what a good geared hub kit costs. The battery is the all important factor for D/D hubs, even 48v isn't exactly great for D/D you need more current and voltage typically 60v for a more effiecient moped.

Okay thanks for that, I'm looking at getting a good 52v battery, that paired with a kt controller will hopefully be okay.. can I ask, if I upgraded to a bafang mid drive or even a geared hub motor, would that same kt 30/40amp controller work with it?

 

[Sharding1995]

How does this look? Is this a kt compatible controller and lcd screen? Thanks for all the help everyone! Learning more here in a day than anywhere else in past 2 weeks lol

36/48V 1500W 45A Sine Wave Controller+LCD3+Throttle+PAS+Brakes+Speed Sensor | eBay

Applicatoin: Max. 36V or 48V 1200W 1500W Motor. PAS- 8 Magnets 1. Full Bar Twist Throttle 1 pair (Thumb Throttle). Cruise and constant speed: With the setting and display of the cruise, achieving to automatically maintain the vehicle speed, so that the vehicle drives at a constant speed;.

www.ebay.co.uk

 

[Sharding1995]

As Nealh says, a lot of people fall into the large DD trap, because of (apparent) price and (apparent) superpower. I certainly might have done so if I had not read extensively (mainly on this site) before buying. Probably usually first time ebikers wanting to test the waters and see whether ebike is for them, and so want to minimize budget. A quick look on ebay makes £300 appear a feasible budget, and £500/£600 seems an awful lot more for what may just end up as a few weeks (days?) experiment.

(1) Anyone who reads this site in advance is unlikely to fall into that trap, and if they ask a 'what should I buy' question are likely to very strongly warned of it.

(2) However, I wonder if there are clear suggestions for the best thing to do for people who have fallen in, and come to this site for suggestions of the next best steps they should take?

I and many others can help with (1). On the other hand, I (and I think many of us) don't have the knowledge to make a constructive contribution to (2). Perhaps it would be worth a sticky thread contributed to by those that do?

That sort of thread would really help.. what motor is best for what situation... what controller and screen works with what motor etc, if such a thread is made please let me know

 

[Nealh]

How does this look? Is this a kt compatible controller and lcd screen? Thanks for all the help everyone! Learning more here in a day than anywhere else in past 2 weeks lol

36/48V 1500W 45A Sine Wave Controller+LCD3+Throttle+PAS+Brakes+Speed Sensor | eBay

Applicatoin: Max. 36V or 48V 1200W 1500W Motor. PAS- 8 Magnets 1. Full Bar Twist Throttle 1 pair (Thumb Throttle). Cruise and constant speed: With the setting and display of the cruise, achieving to automatically maintain the vehicle speed, so that the vehicle drives at a constant speed;.

www.ebay.co.uk

Hallo have always been quite expensive imho so have a look on Aliexpress first for price comparison, yes it is a KT controller.

 

[Nealh]

Okay thanks for that, I'm looking at getting a good 52v battery, that paired with a kt controller will hopefully be okay.. can I ask, if I upgraded to a bafang mid drive or even a geared hub motor, would that same kt 30/40amp controller work with it?

Mid drive have their own inbuilt controller , it will work with a geared hub 500w or 800w one, Either Bafang hub or AKM hub who have a 800w geared hub.

 

[Sharding1995]

Hallo have always been quite expensive imho so have a look on Aliexpress first for price comparison, yes it is a KT controller.

Okay cheers, it says max amps 45... I thing that particular controller has a rated current of 22amps...
What would be a safe amount of amps to limit the controller too without the risk of damaging components? For arguments sake let's say I have a battery that can exceed 45 amp continuous and by hub motor is good upto 5kw lol. I just wanna buy something that I wont have to replace if I upgrade other components and something that I dont have to worry if I'm pushing a little too much amps.

Also if I put a 52v battery in, that means I'll be pushing less amps than 48v at the same speed? If so is it the same amount of work for a controller?

I have a basic understanding of batteries and electronics thanks to making ecigs, I just dont know the "safe boundaries" when it comes to bikes...

Sorry for all the questions, I'll run out of them pretty soon I think!

 

[Nealh]

If upping the voltage you need to know if the lcd will also work on that voltage.
Yes more voltage means less current is required, a lot depends on the battery continuous rating and the hub rating used. D/D hubs don't have the planetary nylon gears of geared hubs so can take abuse, with geared hubs you need to be a bit more careful otherwise you can melt the gears and cook the copper windings.

Typically a 250w geared hub is better then a 1kw D/D hub in most uses, they can output 500 - 800w of power if needed occasionally. The battery doesn't have to BE large or as heavy, voltage wise 36v is more then capable.
Geared hubs are easier to pedal without power if need be, they are lighter some less then 2kg capable of 45nm of torque.

The only real benefit of a D/D hub is for high voltage, current and speed, for all of those you are in moped territory. Anything less then 52v nom stick to geared hubs.